High Performance Pitch Shifter

Patheros · January 26, 2022, 2:38am

So I’m curious if anyone knows of a high performance pitch shifter. For my IceTray module I have a built in pitch shifter. For it I copied the HCTIP module from Bidoo. Its using pffft.h to do a fast fourier transform, which I understand is never going to be fast, but I thought I would at least ask and see if anyone had any ideas.

pgatt · January 26, 2022, 5:08am

@synthi

Jens.Peter.Nielsen · January 26, 2022, 5:26am

I was studying this - may be of some use to you:

DaisySP/Source/Effects/pitchshifter.h at master · electro-smith/DaisySP · GitHub

Pitch shifting

Disclaimer: I’m a beginner.

fractalgee · January 26, 2022, 8:23am

github.com

squinkylabs/SquinkyVCV/blob/main/docs/shifter.md

# Booty Shifter frequency shifter <a name="shifter"></a>

**Booty Shifter** is a frequency shifter inspired by the Moog/Bode frequency shifter module.

![booty shifter image](./booty-shifter.png)

The name "Booty Shifter" is a nod to the classic analog module, as well as to a black cat named Booty.

Booty Shifter  will take an audio input and shift the frequencies up or down. This is not like a pitch shift where harmonics will remain in tune; it is an absolute frequency shift in Hz, so in general **harmonics will go way out of tune.** It is similar to a ring-modulator, but less extreme and more versatile.

When the original module was released long ago it cost around $1000. More recent Eurorack frequency shifters are still very expensive, because the frequency shifter requires a large number of components, and must be carefully calibrated.

## Getting good sounds from Booty Shifter

Feed in music and shift the frequency a good amount.

Feed in **speech or radio** and shift it.

Feed the CV from a **sequencer** to sequence the mayhem.

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mosphaere · January 26, 2022, 8:24am

Have a look at VCV Library - Squinky Labs Booty Shifter too. Squinkys Modules are very CPU-friendly.

Squinky · January 26, 2022, 3:56pm

This is a frequency shifter, not a pitch shifter.

Patheros · January 27, 2022, 1:18am

Yeah unfortunately I need a pitch shifter to correctly offset playback speed changes.

I did find 2 more pitch shifters. Both use less CPU but don’t sound as clean as HCTIP. That might just be the ultimate trade off.